Comparison of two Caenorhabditis genes encoding FMRFamide(Phe-Met-Arg-Phe-NH2)-like peptides

We have identified a gene encoding multiple FMRFamide-like peptides in the necromenic nematode Caenorhabditis vulgaris. This gene, Cv-flp-1, shares strong sequence homology in the coding regions with the flp-1 gene from the related free-living soil nematode C. elegans. The predicted neuropeptide precursor proteins differ by only four conservative amino acid changes, none of which affects sequences of the predicted neuropeptides. DNA sequences in the non-coding areas are less conserved, but areas of sequence homology are found in introns and in 3' and 5' non-translated regions, suggesting some functional significance for these conserved regions. In C. vulgaris, as was found in C. elegans, two transcripts are presumably produced as a result of use of an alternative 3' splice acceptor site. Lastly, an antibody specific for the RF-moiety of FMRFamide stains a similar subset of cells in C. elegans and C. vulgaris. These results indicate that the function and regulation of the peptides are likely to be conserved in both species.